Meng'er Zhang accidentally punched Simu Liu in the face during their first fight scene together.
The 'Shang-Chi and the Legend of the Ten Rings' actress - who has made her acting debut as Xu Xialing in the Marvel Studios blockbuster - admitted she was "nervous" and went a bit too far after some encouragement from her co-star.
She told Collider: "My favourite memory on set was my first fight scene with Simu and I did punch him in the face - and yes, audiences can see it in the film!
"I was nervous because that was the very first fight scene and Simu encouraged me. He said, 'It's OK, it's OK, just go for it, you can't hurt me!'
"So I went for it, I just got into my character. It was an accident but, to be honest... it felt good. [laughs]"
Zhang described working on the movie as a "dream come true" when it comes to her first mainstream project.
She added: "I didn't have any camera experience before, so I didn't know what it was like.
"The whole journey was just like... a masterclass to me. Because I got to work with so many legends, you know?
"It's like a dream come true... I just learned so much from them."
Meanwhile, the actress didn't actually know she was auditioning for a Marvel movie until she was flown out for a screen test with Liu.
She said: "That's when I found out I was auditioning for 'Shang-Chi'. After five days of that screen test I got a message from my lawyer.
"I didn't read through, I just scrolled down to the very bottom and I saw, 'Welcome to the Marvel Universe'! I can keep big secrets. I didn't tell my parents - believe it or not, I didn't tell them!
"I kept the secret, you know? And when I had to fly to shoot the film, I had to tell them and they couldn't believe me.
"I said, 'OK it's a film, it's a Marvel film'. And my mom was like, 'No, you're lying'. 'No I'm not!' They're really excited!"